Shed Workshop 13 June: An antenna ecosystem and Constructing a simple SSB Transceiver

Controlling field equipment under an ecosystem approach

The June Shed Workshop was held a week later than usual – from 1pm to 3pm on Sunday 13 June 2021 at Mike ZL1AXG’s QTH due to Queen’s Birthday weekend getting in the way.

Mike ZL1AXG and Bernard ZL2BD gave an introduction to the concept of an antenna ecosystem, in which a range of antennas could be controlled by a single microprocessor control system.  This includes remote antenna switches (with just one antenna cable into the shack), 4 square switching, directional switching of beverage antennas or similar, tuning of magnetic loop antennas, and rotator control for beam antennas.

Mike ZL1AXG also introduced Charlie Morris’ Simple Transceiver for 80m SSB. He showed off some of the modules that are under construction, and outlined in a block diagram the design of the transceiver. He demonstrated how the audio modules could be tested using a multi-meter, signal generator and oscilloscope by inputing a signal from the signal generator at 1KHz in the front end of an amplifier and measuring the voltage on the oscilloscope or multimeter at the output end.

Social Group Meeting 25 May 2021 – special visitors from up country

Several members of Branch 50 NZART travelled up to Wanganui on 27 March to visit the Wanganui Vintage Radio Museum that was established by Graham, ZL2AHR and his XYL Val, ZL2FO. Ian ZL2AM from Fielding, also joined us as he is heavily involved in the museum’s operations.

The team of Graham, Val and Ian then reciprocated in attending our informal social group meeting on 25 May 2021. We invited all Branch 50 members and their XYLs to attend and the afternoon tea was very well attended. The enhanced afternoon tea supported by club funds was well received. The social group meets every fourth Tuesday from 1.30pm to 3.30pm at George ZL2AG’s QTH at 14 Vasanta Avenue, Ngaio.

Sunday 16 May Meeting with ZL2HUT

Our May Meeting was scheduled for 1pm on Sunday 16 May 2021 at the Waitohi Hive Maker Rooms (Johnsonville Public Library).

We welcomed back former RSM manager Ian Hutchings ZL2HUT, who will give a presentation on Mana Coastguard communications upgrades. This was a very interesting presentation. The Mana Coastguard marine band repeater arrangements involve multiple linked repeaters on Kapiti Island and on the mainland. There had been issues with access to the repeater on the coast south of Titahi Bay. The problems were solved, but not without quite of work as the system was not well documented and there proved to be access issues with one of the repeater sites. A new site is being scoped for the South Coast on Cook Strait. This provides for some interesting possibilities for amateur radio use, in addition to solving coverage in Cook Strait, particularly near the shoreline.

The meeting also considered the AREC remit for the NZART Annual Conference, and approved the proposed changes to the NZART Constitution.

The meeting concluded with tea or coffee upstairs in the cafe courtesy of branch funds.

Shed workshop 2 May 2021

Bernard presented a primer on RX antennas in his garage on Sunday 2 May at 1pm. This included a summary of why TX and RX antennas can desirably be different and a summary of typical options for RX antennas. 

He also give an update on his latest Mag Loop experiments (including this large 6m tuned loop for 80m and 40m).

The meeting concluded with tea, coffee and biscuits.